The day began with a renewal of shipping raids, this time in the Thames Estuary, designed to act as feints for the main assault which was picked up by radar over Cap Gris Nez at 1030 hours. Three waves totaling 100 aircraft came at half-hour intervals at 14,000 feet.

A cloud-layer at about 7,000 feet meant that the Observer Corps had to rely on sound plotting and it was not until an hour after the build-up over France that the 11 Group controller realised that forces were heading for Kent and Surrey sector stations. Sixteen squadrons were despatched to intercept, of which two, to guard Kenley and Biggin Hill, became involved in a dog-fight over Surrey. One formation of German bombers, which had split off from the main group, attacked Biggin Hill at noon and was not seen by the 12 Group Squadron flying on airfield protection patrol. From high altitude delayed-action bombs were dropped which damaged the airfield surface and the village but once again did not render the former unserviceable.

A second mass attack began at 1330 hours when raids of 6 + , 12 + and 20 + crossed the coast between Dover and Dungeness, and then split up, sections heading for Biggin Hill, Shoreham, Kenley and Tangmere. Eight squadrons of fighters were ordered up and the raids retreated just before four o’clock. During this attack the radar stations at Dover, Pevensey, Rye, Foreness, Fairlight, Whitstable and Beachy Head were out of action due to a mains supply failure.

No sooner was this over than a third attack developed from Dover in waves, the objectives being Kenley, Biggin Hill, North Weald, Slough, Oxford and a convoy code-named ‘Bacon’.

Detling airfield was hit by forty to fifty bombs which set fire to oil-tanks, cut the mains cable, cratered the roads and damaged one Blenheim. It was estimated that the station would not be serviceable until 0800 hours on the 31st.

Far worse than this, one small raid of less than ten confused the defences by flying to the Thames Estuary and then turning south to Biggin Hill where at six o’clock, by low-level bombing with 1,000-pounders, the airfield was reduced to a shambles. Workshops, the transport yard, stores, barracks, the met. office, the armoury, WAAF quarters, and another hangar were wrecked; the power, gas and water mains were severed and all telephone lines north of the camp were cut in three places. Amid the rubble and fires casualties were very heavy, with thirty-nine dead and twenty-six injured — a number of them in a shelter trench which received a direct hit. Somehow the mess was cleared up and the station put back on an operational footing.

During the period another raid had come in over Sheppey, and, although intercepted, part of the force managed to reach Luton, where ten bombs were dropped and one hit the Vauxhall motor works, the total casualties including over fifty dead.

A section of Spitfires of No. 616 Squadron prepares for an evening take-off from RAF Kenley in late August 1940.

Barrage balloons come down in flames after being shot by German fighters, 30 August 1940.

A Heinkel He 111 of KG 1 lies in a Surrey field at mid-day on 30 August 1940. The aircraft was one of a large formation that caused heavy damage to Biggin Hill, but was intercepted by Nos. 79 and 610 Squadrons. The crew of five were captured but one died from injuries.

An air raid shelter at Biggin Hill that took a direct hit during a Luftwaffe raid on 30 August 1940. Thirty-nine RAF personnel were killed.

A bandaged Flt Lt Geoffrey Matheson of No. 222 Squadron surveys the burnt-out remnants of his Spitfire after he had crash-landed near the Sittingbourne Paper Mills on 30 August 1940. The aircraft has exploded shortly after Matheson got the battle-damaged Spitfire on the ground and he was lucky to escape with relatively minor wounds.